For culturing animal cells, a polystyrene culture dish for tissue culture, to which various ionic groups are introduced by plasma irradiation or the like, has been broadly used. The degree of ionization by introduction of ionic groups is, however, not invariable, and the surface composition is not defined chemically. Nevertheless, even with such an ordinary polystyrene culture dish for tissue culture, an immortalized cell line can proliferate well in many cases.
On the other hand, since primary animal cells isolated from tissues constitute heterogeneous cell populations, they have not been habituated to a cultivation system and their proliferation rates are low in many cases. As the result, when a polystyrene culture dish for tissue culture is used, a basic research, and development of regenerative medicine and a biopharmaceutical using animal cells are difficult. Further, with a polystyrene culture dish for tissue culture, even when a proliferation factor or a cytokine is added, a target cell can be hardly proliferated selectively. Further, a contamination cell other than a target cell cannot be removed from a heterogeneous cell population. Consequently, a research and development of regenerative medicine or a biopharmaceutical is difficult.
To overcome the drawback of an ordinary polystyrene culture dish for tissue culture, as a coating material an adhesion factor, such as fibronectin and collagen, a partial peptide of an adhesion factor, polylysine and an extracellular matrix such as a basement membrane are used. Such coating materials are however expensive, and the effect on culture has been restricted to limited cells.
Meanwhile, for a culture of animal cells, a serum-containing culture medium, to which a high concentration of serum is added, is generally used. However, since serum is a natural ingredient, a serum-containing culture medium has drawbacks of uncertain composition, lot-to-lot variance, a risk of contamination of a pathogenic microbe, and a risk of an immunoreaction. Therefore in using a serum-containing culture medium, variance in cell proliferation (differentiation) is apt to appear. For overcoming the drawbacks, development of a serum-free culture medium is underway. However, since a serum-free culture medium does not contain an adhesion factor of serum, when culture in an ordinary polystyrene culture dish for tissue culture is attempted, there is a drawback in that adhesion and proliferation of a cell becomes difficult.
Further, although a plastic culture dish, to which NH2 group, or COOH group is added, is on the market recent years, the influence on cell proliferation has not been clarified thoroughly yet. Meanwhile, a culture dish provided with a self-assembled monolayer (SAM) on the culture dish surface has been investigated in some studies. Changing a combination of 3 types of functional groups (CH3/OH, CH3/COOH, CH3/NH2) composing an SAM and their contents, influence on adhesion of a cancer cell and an established (immortalized) cell line was investigated in the presence of a 2 to 10% fetal bovine serum (Non Patent Literature 1).
Further, influence of a combination of 2 types of functional groups on a short term proliferation of a cancer cell and an established (immortalized) cell line has been investigated (Non Patent Literature 2).
Adhesion of a vascular endothelial cell to SAM with an RGD peptide has been reported (Non Patent Literature 3).